Answer: Option B
Explanation: The peak of a wave can be called the "positive" part of the wave, and the trough part of a wave can be called the "negative" part of a wave.
So if these two parts of the wave interfere with each other, they cancel each other (because one is "positive" and the other "negative")
This effect is called Destructive Interference (in the case where two peaks or two troughs interfere, the phenomenon is called constructive interference)
Then the correct option is B